SA Graan Augustus 2015

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Augustus 2015
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Lupines have various uses, i.e. using it as a rotation crop, a
pasture crop and a silage crop. As a rotation crop, lupin seed is
sown directly into wheat stubble with no additional nitrogen (N)
and can be used to reduce excessively high levels of other macro
nutrients.
As a pasture crop especially for sheep, grazing is often restricted
because of high concentrations of alkaloids in the young leaves and
growth points. As the plant matures, more parts of the plant are
eaten. The greatest value however of lupines is found in the dry
summer months in the winter rainfall region, when sheep pick up
the fallen seeds and also graze the stubble.
Lupines can also be used for silage production, because the spe-
cies have a high green matter, moisture and protein content. Ad-
ditionally, the high seed production of this species provides a
concentrated form of carbohydrates which becomes very valuable
in the silage making process.
Soil conservation and health benefits
In general it is known that lupines are adapted to poor and slightly
acid soils, but they do however have high growth requirements.
Lupines are used as green manure and in rotation with cereals
because they are capable of fixing nitrogen from the atmosphere
and converting it to a usable form.
Poorly fertilised lupines can exhaust the soil and leave it even
poorer than before. This is where lupines can have great value in
soils that have extremely high levels of nutrients that have built up
over time. Lupines are also well-known in weed management and
between fields of cereal crops to keep diseases from spreading.
Atmospheric nitrogen fixation rates of up to 400 kg N/ha has been
observed in Europe and Australia.
Management challenges
One of the major challenges regarding the use of lupines for grazing
purposes is that they often contain high levels of alkaloids. If large
quantities of the alkaloids are ingested by ruminants, it can cause
significant metabolic disorders in livestock and can eventually lead
to death. Another poisoning that can be experienced is Phomopsis
poisoning, which entails the ingestion of lupin stubble that has a fun-
gus growing on it, especially after rain during summer or autumn.
Animal production aspects
With a crude protein content of 19%, studies have shown that
it is possible to carry six sheep/ha for eight months of the year.
Lupines are a concentrated source of both protein and energy and
the greatest form of lupin utilisation in Australia is as a whole-grain
feed for grazing sheep, to supplement low grade roughage diets.
Livestock production responses vary depending on the quality of
the forage on offer. The efficiency of utilisation of lupin grain var-
ies from live weight change of 0,8 g/g of lupin dry matter for low
quality roughages where sheep are losing weight rapidly, to live
weight gains of 0,2 g/g to 0,3 g/g lupin dry matter where roughage
quality is adequate to support maintenance or slow growth.
Lupin supplements generally result in higher intake, live weight
gain and wool growth than comparable supplements of cereals.
This is primarily due to their protein contribution to rumen micro-
bial protein synthesis, but also possibly due to rumen bypass protein
effects, higher metabolisable energy content and fewer distur-
bances to fibre digestion which often accompanies the fermentation
of cereal starch.
Conclusion
Annual lupines are promising legume crops for green manuring
and forage. The composition of the seed and especially the high
protein content makes lupines highly suitable for livestock diets as
a protein-rich product in intensive farming systems. Since it often
can grow on land unsuitable for other crops (too saline, heavy,
acid or poor), the development of cultivars adapted to tropical
African conditions is highly recommended.
For more information, contact Dr Wayne Truter at wayne.truter@
up.ac.za, Prof Chris Dannhauser at Dr Hen-
drik Smith at or Mr Gerrie Trytsman at
References
Dickinson, E.B., Hyam, G.F.S., Breytenbach, W.A.S., Metcalf, W.D., Basson, W.D.,
Williams, F.R., Scheepers, L.J., Plint, A.P., Smith, H.R.H., Smith, P.J., van Vuuren,
P.J., Viljoen, J.H., Archibald, K.P. and Els, J.N. 2004. Kynoch pasture handbook.
Kejafa Knowledge Works, Maanhaarrand.
6: Sweet lupines (L. angustifolius) are planted for harvesting their seeds.
7: Sweet lupine trial with one bitter cultivar (SSL10 with the blue flowers).
ON FARM LEVEL Conservation agriculture
CONSERVATION AGRICULTURE
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